Some possible tissue assay methods for n nutrition assessment of Pinus Taeda L.

Abstract

Studies were conducted on loblolly pine to test the sensitivity of a number of N assay methods which would show the greatest increase of N in fertilized over unfertilized trees as the most indicative of the N status of stands. In November, total N in xylem and fresh needlefall was more sensitive than that in needles. Current needles and twigs collected in September were more sensitive than 1 year old tissue. Needles and twigs appeared to have similar sensitivity. Soluble‐ and arginine‐N appeared more sensitive than total N in needles and twigs; however, these N fractions were too variable to be statistically evaluated as well as their laboratory procedures not easily adapted for routine use.